UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460



### MEMORANDUM OFFICE OF CHEMICAL SAF ETY AND POLLUTION PREVENTION



### PC Code: 080803 DP: 409990, 410271 Date: May 13, 2013



### SUBJECT: Review of Atrazine Ecological Monitoring Program

- Proposal for 2013, dated March 8, 20 1 3; submitted by Syngenta Crop Protection, LLC.



### TO: Monica Wait, Chemical Review Manager Patricia Parrott, Chief Risk Management and Implementation Branch III Pesticide Re-Evaluation Division

FROM: l Frank T. Farruggia, Ph : D., Biologist James Hetri ck, Ph.D., Senior Science Advisor Environmental Risk Branch III
Envirorunental Fate**~i**


### THROUGH: Dana Spatz, Chief

# ~ Rosanna Louie-Juzwiak, RAPL Environmental Risk Branch III 

### Environmental Fate and Effects Division

In a proposal for conducting the Atrazine Ecological Monitoring Program (AEMP) in 2013, Syngenta has requested to decommission 20 com/sorghum monitoring sites and the remaining

two sugarcane sites. Syngenta proposes to continue monitoring at nine watershed sites.

The 20 com/sorghum sites in the request include: IA-03

, IL-10 1

, 

### IL-12, IL- 14

, IL-15, IL-16, IL17, 

### IN-12, KS-01, KS-02, KS-03, M0-04A, M0-05, M0-05B, M0-06, NE-05, NE-09, OH-05\ OH-06 and TX -02

. The two sugarcane sites included in the decommissioning request are LA-01 

### and LA-03.

1 This site was considered acceptable for decommissioning in 2012 ; however

, the registrant continued to monitor to evaluate their ongoing projects in the watershed.



# '

### 2 After reviewing the results of the monitoring data from the AEMP and the registrant’s rationale for the decommissioning requests, EFED can conc ur with decommissioning all of the proposed sites listed above. The vulnerability of these sites to atrazine runoff is well understood, and the 60-day running average atrazine concentrations in these watersheds are below the current level of concern (LOC) of 10-ppb atrazine over a 60-day period (http://www.epa.gov/pesticides/reregistration/atrazine/atr azine_update.htm#post-red).

The 60-day running average atrazi ne concentrations in the IA-04, IA-05, LA-04, MO-07, MO08, and TX-01 watersheds have been above the atra zine LOC for at least two of the last three years ( Table 1 ), and thus concerns remain regarding the health of the aquatic plant communities in these watersheds. Thus, in addition to MO -1, MO-2 and NE-04, where Syngenta has focused their stewardship efforts, IA-04, IA-05, LA-04, MO-07, MO-08, and TX-01 will continue to be monitored as part of the AEMP in 2013.

As for the remaining two sugarcane sites in the AEMP, EFED can concur with the decommissioning request, as recent monitoring results have shown atrazine concentrations below levels of concern ( Table 2 ).

Table 1. Summary of atrazine co ncentrations in corn/sorghum AEMP sites from the past 3 year s. Sites decommissioned in 2012 are indicated with “NA”. Bold ed values indicate an LOC exceedance.

Site ID Max 60

‐ day Avg Value ( μ g/L)

2010 2011 2012

IA

‐ 03 10.5 4.9 2.0

IA

‐ 04 10.4 4.3 10.9

IA

‐ 05 11.3 12.8 7.0

IL

‐ 10 0.4 1.4 0.7

IL

‐ 11 1.1 1.8 NA

IL

‐ 12 6.9 4.6 5.6

IL

‐ 13 0.7 1.4 NA

IL

‐ 14 5.2 4.9 3.4

IL

‐ 15 6.8 6.8 7.0

IL

‐ 16 7.5 2.6 9.5

IL

‐ 17 5.7 17.2 6.3

IN

‐ 12 4.5 4.2 1.5

KS

‐ 01 5.4 1.5 2.6

KS

‐ 02 8.9 3.5 1.6

KS

‐ 03 11.6 5.9 4.4

LA

‐ 04 6.3 27.4 11.5

LA

‐ 05 3.3 4.2 NA

MO

‐ 01 5.1 4.5 1.4

### 3 MO

‐ 02 8.4 6.6 1.8

MO

‐ 04A 8.7 11.5 7.5

MO

‐ 05 12.9 6.2 4.0

MO

‐ 05B 12.3 8.3 5.6

MO

‐ 06 6.3 6.9 3.7

MO

‐ 07 20.2 14.6 11.9

MO

‐ 08 14.5 14.1 11.2

NE

‐ 04 34.7 3.4 2.4

NE

‐ 05 8.1 2.3 1.0

NE

‐ 09 6.2 1.2 4.9

OH

‐ 05 2.0 1.4 1.9

OH

‐ 06 3.8 5.9 5.2

TX

‐ 01 13.5 3.0 15.6

TX

‐ 02 3.7 0.2 3.3



### Table 2. Summary of atrazine concentrations in the remaining active Louisiana sugarcane AE MP sites from 2005-2012. Bolded values indicate an LOC exceedance.

Site ID Year Max 60

‐ day Avg Value ( μ g/L)

LA

‐ 01 2005 7.6

2006 2.3

2007 12.7

2008 8.1

2009 10.0

2010 9.5

2011 5.3

2012 2.2

LA

‐ 03 2005 14.3

2006 3.7

2007 3.0

2008 6.3

2009 2.1

2010 0.6

2011 0.8

2012 0.6